iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 6+, released on 2019-01-22T18:10:17Z. The update package is 325.06 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 268ece6e7f6c83486bc6e00b38a30f5fa676b45d.zip.